The present invention relates to solenoid actuated control systems in which a plurality of instruments are selectively actuated by a single solenoid device, and more particularly to a solenoid actuated control system for a tape recorder.
In the usual cassette tape recorders, it is necessary upon timer record to shift a cassette tape recorder in its record mode and to actuate a pause mechanism in order to prevent a pinch roller from being kept in press contact with the corresponding capstan for a long time.
By so setting the cassette tape recorder, connecting of a source of electric energy to the cassette tape recorder at a time preset by the timer causes the pause mechanism to be released, putting the tape recorder on record mode. Subsequently, when the tape has been wound up to an end, an auto stop mechanism operates to cause the tape recorder to cease operation.
During one cycle of steps required for timer record, the step of releasing occurs twice, i.e., once upon releasing the pause mechanism and the other upon releasing the appropriate keys to stop the tape travelling when the tape has been wound up to an end.
The usual cassette tape recorders have a first group of keys including a record key, a play-back key, a rewind key and a fast forward key; a latch plate for latching the first group of keys to their retracted operative positions; and a release key which when depressed causes the latch plate to release the first group of keys. For timer record, the tape recorder is equipped with an electric circuit to detect when the reel comes to a stop. A solenoid device causes the latch plate to release the first group of keys when it is energized in response to the electric circuit. Also provided are a pause mechanism to give a pause upon record and a release mechanism to release the pause mechanism. For timer record, another solenoid is conventionally provided to release the pause mechanism when the tape recorder is connected to a source of electric energy at a time preset by a timer.
The problem with the previously described conventional cassette tape recorder is that two solenoid devices are needed for performing the two releasing steps which occur at two different instances, contributing to the complexity in construction and to an increase in manufacturing cost.
To cause a single solenoid device to perform the two releasing steps there can be provided an appropriate selector mechanism which engages a plunger of the solenoid device selectively with instruments to be actuated to perform the two releasing steps required during one cycle of timer record. The selector mechanisms, having been proposed for this purpose are, however, complicated in construction, tending to result in unstable operation.